EP 2175443 A1 discloses a statistical detector that is used for detecting watermark data within an audio signal. Multiple peaks in a correlation result values sequence of length N (resulting from a correlation of a reference sequence with a corresponding section of the received audio signal) are taken into account for improving the detection reliability. The basic steps of this statistical detector are:                Find peak values ν1 ≧. . . ≧νM in the correlation result values sequence for each candidate watermark symbol, where M is the number of peaks taken into consideration.        Calculate the false positive probability denoted as P(M) for the M peak values that the candidate watermark symbol is embedded.        The candidate watermark symbol with the lowest probability P(M) is selected as current watermark symbol.        
P(M) is the probability of falsely accepting a candidate watermark symbol. It describes the probability of M or more correlation result values in an unmarked case (i.e. no watermark is present in the corresponding original signal section) being greater than or equal to the actual M peak values under consideration.